Polysaccharide-producing enzyme (glycosyltransferases) such as glucosyltransferase(GT) and fructosyltransferase(FT) are previously utilized for, for example, the industrial production of dextran, but since this polysaccharide-producing enzyme has, in relation to living bodies, a plaque formation ability in the oral cavity, they have been regarded as the most important pathogenic factor of dental caries, and therefore, their utilization has been limited.